Liquid Vaporization Device and Method

ABSTRACT

A vaporizer device and associated methodology for providing accurate sampling through substantially efficient, complete and uniform single pass vaporization of a liquid sample by avoiding liquid pre-vaporization and downtime attributable to system damage from incomplete vaporization, particularly in the distribution, transportation, and custody transfer of natural gas. The vaporizer device includes at least one input port for receiving a liquid sample, a channel for directing the liquid to a vaporizer core and a heating assembly within the vaporizer core configured to flash vaporize the liquid sample. The vaporized sample can then be passed to an outlet for sample analysis.

FIELD OF THE INVENTION

This invention relates generally to a device and method for theefficient vaporization of heterogenous hydrocarbon containing liquidsand particularly natural gas liquids such as Natural Gas Liquid (NGL)and cryogenic Liquid Natural Gas (LNG). The invention is particularlyuseful for uniform flash vaporization of liquid samples, withoutpre-vaporization, extracted from a source in order to provide uniformsample vapor for accurately determining the constituent components orenergy content of the sample.

BACKGROUND OF THE INVENTION

Natural gas is a combustible, gaseous mixture of several differenthydrocarbon compounds now often extracted by fracking from undergroundreservoirs within porous rock. The hydrocarbon constituents of naturalgas vary depending on the geographic location of the reservoir and evenlocally where the composition of gas extracted from a single source canvary. Regardless of any variations, however, the primary component ofnatural gas is methane, a colorless, odorless, gaseous saturatedhydrocarbon. Methane usually accounts for 80% to 95% of any natural gassample and the balance is composed of varying amounts of ethane,propane, butane, pentane and other hydrocarbon compounds. Some extractednatural gas may contaminated with small amounts of impurities thatrequire detection and removal. Sour gas can comprise trace contaminantssuch as, Mercury (Hg), Hydrogen sulfide (H₂S), Carbonyl sulfide (COS),Mercaptans (RSH), and aromatic compounds including those from the groupknown as BTEX (Benzene, Toluene, Ethylbenzene and Xylene).

Natural gas is used extensively in residential, commercial andindustrial applications. It is the dominant energy used for home heatingwith well over half of American homes using natural gas. The use ofnatural gas is also rapidly increasing in electric power generation andas a transportation fuel.

Natural gas is commercially measured by the amount of energy itcontains. The common unit of measurement in the United States is theBritish Thermal Unit (BTU). One BTU is equivalent to the heat needed toraise the temperature of one pound of water by one-degree Fahrenheit atatmospheric pressure. A cubic foot of natural gas has about 1,027 BTU(1083.54 kilojoules (kJ)). Natural gas is normally sold from thewellhead, i.e., the point at which the gas is extracted from the earth,to purchasers in standard volume measurements of thousands of cubic feet(Mcf). However, consumer bills are usually measured in heat content ortherms. One therm is a unit of heating equal to 100,000 BTU (105,505.59kJ).

Three separate and often independent segments of the natural gasindustry are involved in delivering natural gas from the wellhead to theconsumer. Production companies explore, drill and extract natural gasfrom the ground; transmission companies operate the pipelines thatconnect the gas fields to major consuming areas; and distributioncompanies are the local utilities that deliver natural gas to thecustomer.

In the United States alone, natural gas is delivered to close to 200million consumers through a network of underground pipes that extendsover a million miles. To produce and deliver this natural gas there areover a quarter-million producing natural gas wells, over one hundrednatural gas pipeline companies and more than a thousand localdistribution companies (LDCs) that provide gas service to all 50 states.

Pipeline companies transport gas from sellers, such as producers ormarketers, to buyers, such as electric utilities, factories and LDCs.LDCs can choose among a variety of sellers of natural gas and customersmay choose its LDC supplier. The consumer's LDC, as the owner/operatorof the distribution network, delivers the gas to the consumer, but theLDC only charges the consumer for delivery of the gas and theindependent supplier bills for the gas. Not only upon extraction formthe ground but at each of the stages of custody transfer, energy contentanalysis provides critical value information to the purchaser.

An important part of the art in gas sample conditioning relates to theprocess of vaporization of a liquid sample extracted via a probe from agas pipeline or source. Once the liquid sample is extracted, it istypically communicated from the take-off probe through acorrosion-resistant super alloy, such as stainless-steel tubing, with arelatively small diameter to a sample conditioner for vaporization,pressure regulation, and ultimately to an analyzer, such as achromatograph, for analysis.

The distance between the liquid probe takeoff and the analyzer oftenexceeds 30 feet (9.144 meters) and may even exceed 100 feet (30.48meters). When, as is typical, the extracted liquid sample is vaporizedproximate to the probe, the vaporized sample must move physically fromthe probe at a high pressure, e.g., 2000 psig (13789.51 kPa), to theanalyzer while preserving the vapor stage and being subject tosubstantial pressure reduction to a relatively low-pressure zone, e.g.,10-30 psig (68.9 kPa-206.8 kPa), which is an acceptable pressure for atypical analyzer/chromatograph. During the process, it is important toavoid cooling the vapor to a point near the vapor phase curve tominimize the risk of hydrocarbon dew point dropout in the form ofcondensation.

If such condensation occurs, then the input to theanalyzer/chromatograph is fouled with liquid. Introduction of suchliquid invariably compromises the integrity of and damages thechromatographic packing by column bleed, that will, at best, result ingeneration of false readings from ghost peaks, etc., and at worst,destroy the analyzer. Consequently, introduction of liquids into thechromatographic analyzer results in economic harm, at best, from falsereadings, and at worst, decreased system operational efficiencyattributable to taking the fouled unit off-line either for completereplacement or for restoration to an operationally acceptable condition.

Accordingly, it is important to maintain the integrity of the vaporizedliquid sample, without any phase change, for the entire period fromflash vaporization to the time of analysis.

Particularly in the case of hydrocarbon vapor analysis, the issue ofhydrocarbon dew point dropout in gas sampling has been addressed. Dewpoint dropout or phase transition of an extracted pipeline sample isprevented by maintaining adequate post-vaporization heating of pressureregulators, gas lines, and other components, with which the sample gascome into contact following vaporization, during communication to adownstream analyzer/chromatograph or vapor sample collection vessel.Maintaining pressure and temperature of the vaporized sample beyond itsdew point-phase transition envelope, whether the sample comprises aheterogeneous mixture of components possessing a range of vaporcondensation lines or a substantially homogeneous composition with amore predicable phase envelope curve such as LNG, prevents the vapor gassample from reverting to a liquid.

Natural gas sampling systems, however, are typically located in harshenvironments, e.g., where outdoor ambient temperatures can besignificantly below the gas dew point temperature and where dangerousexplosion-prone gas vapors are often permeating into the surroundingatmosphere. Accordingly, any heating mechanism used must adhere tostrict standards in order to generate enough heat to overcome the lowambient temperature while doing so without exposing or releasing the gassamples gases to atmosphere and avoiding safety problems, caused byexposure of vaporized sample gas to electrical wiring, etc.

The American Petroleum Institute (API) has suggested using catalyticheaters to maintain temperature stability of extracted samples to avoidundesirable temperature changes to the gas sample communicated between asource, e.g., pipeline and the analyzer. Catalytic heaters of the typereferred to by the API in its Manual of Petroleum Standards call forheating a sample gas stream throughout a selected portion of a systemwhere the heated sample is then introduced into the analyzer at anacceptable pressure. One preferred system for achieving proper systemthermal stability employs heat tracing to insure substantially uniformtemperature maintenance over the entire length of the vaporized samplepathway during sample communication from take-off to the analyzer. Suchperformance is achieved with use of a P53 Sample Conditioning Systemavailable from Mustang Sampling, LLC of Ravenswood, West Virginia andembodiments disclosed and described in U.S. Pat. No. 7,162,933, theentirety of which is herein incorporated by reference.

Turning to issues associated with vaporization itself, vaporizationdevices in which a low carbon number hydrocarbon liquid, such as naturalgas liquid (NGL) and particularly cryogenic LNG, is vaporized by heatingmay suffer from development of temperature gradations proximate to aliquid sample entry port. In the case of such temperatures exceeding theheat of vaporization, pre-vaporization of the liquid sample may result.When an extracted liquid sample is subject to partial or completevaporization proximate to the vaporizer input, but before reaching aheated vaporization chamber, the integrity of the vaporized sampleexiting a vaporizer may be compromised by undesirable partitioning ofproduct components (lights, intermediaries, and heavies) separating andentering the vaporizer at different times. Such partitioning orseparation will generally lead to faulty energy content andcompositional analysis. Further, in the event that the pre-vaporizedsample is exposed to subsequent cooling or pressure reduction causingre-condensation during the passage into the vaporization chamber,further undesirable compositional stratification/partitioning mayresult. Additionally, where pre-vaporization occurs at the vaporizerinput, the cooling effect created by the expansion of the liquid to gascan generate exterior icing upstream of the entry port and therebyaugment thermal anomalies which further compromise sample uniformity andintegrity.

There exists a need for improvement to the presently accepted andcommonly used systems and methods of vaporization of extracted naturalgas samples for analysis deployable in the field, in distributionsystems, and in transportation. It would be desirable to provide animproved vaporizer that ensures accurate sampling through substantiallyefficient, complete and uniform single pass vaporization of a liquidsample that avoids liquid pre-vaporization and downtime attributable tosystem damage from incomplete vaporization, particularly in thedistribution, transportation, and custody transfer of natural gas.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a device, system and methodthat do not suffer from at least the problems described previouslyherein and which can provide a more efficient and reliable vaporizingdevice for converting LNG or NGL to gaseous vapor.

Yet another object of the invention is to provide a device that deliversbetter heat distribution while reducing the number of hot spots thatlead to the formation of deposits within the device.

It is yet another object of the invention to provide a device that ismore compact, easier to adjust, and less susceptible to mechanicalfailure while also providing for operating efficiencies.

Another object of the invention is to provide a device and method forefficiency vaporizing different types of LNG or NGL samples havingdifferent composition profiles.

Yet another object of the invention is to monitor and control thetemperature of vapor samples exiting the vaporizer device to preventdamage to the vaporizer itself and/or downstream analyzers.

It is a further object of the invention to provide a device, system andmethod that can be used to deliver more accurate measurement of BTUvalues used for custody transfer. Further, to monitor and reduceundesired release from sour gas samples, the device, system and methodcan also be used to accurately measure trace contaminants such as,mercury (Hg), hydrogen sulfide (H₂S), carbonyl sulfide (COS), mercaptans(RSH) and aromatics such as BTEX (Benzene, Toluene, Ethylbenzene andXylene).

Illustrative, non-limiting embodiments of the present invention mayovercome the aforementioned and other disadvantages associated withrelated art liquid vaporization and measurement systems. Also, thepresent invention is not necessarily required to overcome thedisadvantages described above and an illustrative non-limitingembodiment of the present invention may not overcome any of the problemsdescribed above.

To achieve the above and other objects an embodiment in accordance withthe invention includes a vaporizer for a hydrocarbon containing liquid,comprising: a generally elongated tubular body having a first segmentdefining a first end and a second segment defining a second end; aliquid sample port connected to a liquid passage formed integrally inthe first segment, where said first liquid port provides for liquidinput; a liquid channel disposed generally longitudinally along acentral axis of the vaporizer and extending substantially in thedirection of elongation of said tubular body, said liquid channel havinga first end and a second end, said first end of said liquid channelintersecting with said liquid passage to provide a flow path for liquidfrom said liquid sample port therethrough along its length; a liquidflow control element disposed in said first segment of said tubular bodyand configured to intersect the liquid channel; a gap formed in andextending from an exterior surface of the tubular body, the gap defininga generally non-parallel surface directed inwardly toward the liquidchannel and disposed along the length of the liquid channel; a vaporizercore internal to and extending from said second end of said tubular bodyto said second end of said liquid channel; a heating assemblydimensioned for insertion into the vaporizer core and sealinglysecurable to said tubular body, said heating assembly having a flashvaporizing heating element that vaporizes liquid introduced from saidliquid channel; and a vapor discharge outlet port formed in said tubularbody in said second segment spaced from said second end of the tubularbody and intersecting with said vaporizer core.

BRIEF DESCRIPTION OF THE DRAWINGS

The aspects of the present invention will become more readily apparentby describing in detail illustrative, non-limiting embodiments thereofwith reference to the accompanying drawings, in which:

FIG. 1A is a perspective view illustrating a vaporizer device inaccordance with an embodiment of the present invention.

FIG. 1B is a top view of a vaporizer device in accordance with anembodiment of the present invention.

FIG. 1C is a side view of the vaporizer device in accordance with anembodiment of the invention.

FIG. 1D is a two-dimensional view of the vaporizer device perspectivelycut as illustrated in FIG. 1E in accordance with an embodiment of theinvention.

FIG. 1E is perspective cut-away view of the vaporizer device inaccordance with an embodiment of the invention.

FIG. 1F is perspective exploded view of the vaporizer device inaccordance with an embodiment of the invention.

FIG. 1G is a side view of wire mesh in accordance with an embodiment ofthe invention.

FIG. 2A is a cross-sectional view of a vaporizer device with an activecooling element along the bisecting line of FIG. 1C in accordance withan embodiment of the invention.

FIG. 2B is perspective cut-away view of the vaporizer device in FIG. 2Ain accordance with an embodiment of the invention.

FIG. 3A is a cross-sectional view of a vaporizer device having analternative active cooling element in accordance with an embodiment ofthe invention.

FIG. 3B is perspective cut-away view of the vaporizer device in FIG. 3Ain accordance with an embodiment of the invention.

FIG. 4A is a perspective cut-away view of a vaporizer device having analternative metering valve in accordance with an embodiment of theinvention.

FIG. 4B is a perspective cut-away view of the vaporizer device of FIG.4A having an angled thermowell and associated thermocouple in accordancewith an embodiment of the invention.

FIG. 5A is a perspective cut-away view of a vaporizer device having astraight thermowell and associated thermocouple in accordance with anembodiment of the invention.

FIG. 5B is a perspective cut-away view of the vaporizer device havingthe straight thermowell and associated thermocouple in accordance withan embodiment of the invention

DETAILED DESCRIPTION

Exemplary, non-limiting, embodiments of the present invention arediscussed in detail below. While specific configurations and dimensionsare discussed to provide a clear understanding, it should be understoodthat the disclosed dimensions and configurations are provided forillustration purposes only. A person skilled in the relevant art willrecognize that, unless otherwise specified, other dimensions andconfigurations may be used without departing from the spirit and scopeof the invention.

As used herein “substantially”, “relatively”, “generally”, “about”, and“approximately” are relative modifiers intended to indicate permissiblevariation from the characteristic so modified. They are not intended tobe limited to the absolute value or characteristic which it modifies butrather approaching or approximating such a physical or functionalcharacteristic.

In the detailed description, references to “one embodiment”, “anembodiment”, or “in embodiments” mean that the feature being referred tois included in at least one embodiment of the invention. Moreover,separate references to “one embodiment”, “an embodiment”, or “inembodiments” do not necessarily refer to the same embodiment; however,neither are such embodiments mutually exclusive, unless so stated, andexcept as will be readily apparent to those skilled in the art. Thus,the invention can include any variety of combinations and/orintegrations of the embodiments described herein.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the invention. Asused herein, the singular forms, “a”, “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the root terms “include”and/or “have”, when used in this specification, specify the presence ofstated features, integers, steps, operations, elements, and/orcomponents, but do not preclude the presence or addition of at least oneother feature, integer, step, operation, element, component, and/orgroups thereof.

It will be appreciated that as used herein, the terms “comprises,”“comprising,” “includes,” “including,” “has,” “having” or any othervariation thereof, are intended to cover a non-exclusive inclusion. Forexample, a process, method, article, or apparatus that comprises a listof features is not necessarily limited only to those features but mayinclude other features not expressly listed or inherent to such process,method, article, or apparatus.

It will also be appreciated that as used herein, any reference to arange of values is intended to encompass every value within that range,including the endpoints of said ranges, unless expressly stated to thecontrary.

As used herein “gas” means any type of gaseous, vaporizable hydrocarboncontaining liquid matter including natural gas liquids, and liquifiednatural gas, gas mixtures thereof, and equivalents.

As used herein “connected” includes physical, whether direct orindirect, permanently affixed or adjustably mounted. Thus, unlessspecified, “connected” is intended to embrace any operationallyfunctional connection.

In the following description, reference is made to the accompanyingdrawings which are provided for illustration purposes as representativeof specific exemplary embodiments in which the invention may bepracticed. The following illustrated embodiments are described insufficient detail to enable those skilled in the art to practice theinvention. It is to be understood that other embodiments may be utilizedand that structural changes based on presently known structural and/orfunctional equivalents may be made without departing from the scope ofthe invention.

Given the following detailed description, it should become apparent tothe person having ordinary skill in the art that the invention hereinprovides a novel liquid vaporization device and a method thereof forproviding augmented efficiencies while mitigating problems of the priorart.

FIGS. 1A-1F illustrate various views of a vaporizer, or vaporizer device100 in accordance with an embodiment of the present invention. Inoverview, the vaporizer device 100 includes an elongated tubular body102 having at its upper end one or more liquid sample passageopening/ports 104 each associated with a passage or passageway 113 forintroduction into an interior of the vaporizer device 100. The liquidsample ports 104 can include an axially disposed liquid sampleintroduction port 104A and one or more radially disposed liquid sampleintroduction ports 104R or just multiple radially disposed liquid sampleintroduction ports 104R. Unless specifically designated, the term liquidsample port 104 can apply to any one of the ports 104R and 104A.Further, in one embodiment, the vaporizer device 100 could include onlya single radially disposed liquid sample introduction port 104R. Whenmore than one opening/port 104 is included, discharge of liquifiedhydrocarbons, such as NGL or LNG, can be effected via one of theopening/ports 104. Once a liquid sample flows through an opening/port104R through passageway 113 or through opening/port 104A, at least apart of the liquid sample flows to an axially and interiorly directedliquid sample channel 120 for communicating the liquid sample to avaporizer core 130 formed of the space within an elongated, stepped bore135 extending interiorly and axially from the lower end of the body 102to the outlet of the channel 120. Upon vaporization of the liquid samplepassing within the vaporizer core 130, the now-vaporized sample passesto vapor annulus 137 and through the radially oriented vapor outletpassageway 140 to exit the device via a vapor discharge outlet port 118.The vapor outlet port 118 is located proximate the lower end of the body102.

In FIGS. 1D and 1E, a dual port embodiment is illustrated in greaterdetail. As illustrated, liquid sample communication ports 104R andassociated liquid sample passageways 113 may be disposed radially anddiametrically aligned in a generally common, cross-sectional plane withrespect to the body 102 or, may be disposed orthogonally when dictatedby a particular geometry involving confined space limiting access. Theports 104R may be threaded for sealingly securing a fluid input line tothe vaporizer device 100 with a mating fitting (not illustrated).Correspondingly, the vapor outlet port 118 may also feature internalthreading for securing a gas output line via an appropriate fitting (notillustrated).

The geometry of a particular installation may lend itself to an axiallydisposed liquid sample introduction port 104A through the top of body102. As illustrated in FIG. 1B, if unused, the axial port 104A disposedon a top portion of the body 102 can be sealed by a sealing screw/plugelement 116. The port 104A may be threaded for sealingly securing afluid input line to the vaporizer device 100 with a mating fitting (notillustrated). Regardless of the particular geometry, the embodimentcontemplates introduction of a vaporizable liquid through a port 104 toan axially and interiorly directed channel 120 for liquid sampleintroduction to the vaporizer core 130 of the vaporizing device 100 forflash vaporization.

The liquid sample introduced to the vaporizer device 100 through a port104 passes into the axial channel 120 for vaporization. It may bedesirable to include a discharge port 104A/R to accommodate any liquidsample not passing to the vaporizer core 130. Accordingly, theembodiment provides for passage of unused liquid sample through a port104A/R, acting as a discharge port, located with respect to the inputport liquid 104A/R so as to minimize and/or avoid flow rate anomaliesand the like generated by damming or backpressure. Accordingly, thepresence of a second port 104 allows excess liquid entering the housing102 through one inlet port 104 to exit as unvaporized liquid throughanother port 104 regardless of whether the inlet is radially or axiallydisposed.

Turning now to the interior of the vaporizer device 100, the liquidsample channel 120 extends axially for a select distance through thebody 102 to establish a conduit for communicating the liquid sample fromthe passageway 113 to the vaporizer core 130. The depicted embodimentsinclude a liquid flow control element, illustrated in the form of anadjustable valve 107 for controlling the volume of liquid sample flow.The adjustable metering valve 107 is mounted in a radially orientedbonnet 111 which is screwed into side of the body 102 and is disposedperpendicularly along the length of channel 120 and below the ports 104.The valve 107 features a tapering plunger 121 dimensioned for insertioninto a seat 119 that intersects the channel 120. The degree of blockageby the metering valve 107 of the channel 120 flow path is adjustable viaan adjustor element 109. The adjuster element 109 which may take theform of a slotted screw head, rotates relative to the mounting bonnet111 to move the plunger of metering valve stem 107 radially relative tothe channel 120. An automated alternative to the manual adjustor element109 would involve the valve 107 being associated with an actuatablemotor (not illustrated) to control adjustment of the position of thevalve 107. The radially adjustable metering valve 107 has access to thechannel 120 to adjust the volume of liquid flow sample which can make iteasier for operators to control when accessing the vaporizing device 100within, for example, sample conditioning panels. An alternativeadjustable metering valve 402, of which could be incorporated into thevaporizer device 100 instead of the adjustable valve 107, bonnet 111,and tapering plunger 121, is discussed further with respect to FIGS. 4and 5.

A notable feature of the instant embodiment relates to the exteriorrecessed, annular, thermal isolation gap 108 integrally formed in thebody 102 and axially disposed between the liquid sample ports 104 andthe vaporizer core 130 to form a first segment of the body 102 above thegap 108 and a second segment of the body 102 below the gap. To maximizeits thermal isolating capability, the exterior annular gap 108 isdefined generally as non-parallel surfaces extending a radial depthrelative to the body 102 approaching the axial channel 120 toward thecentral axis of the device 100. In the illustrated embodiment of FIGS.1A-1D, the upper and lower surfaces of the gap taper inwardly in a flatplanar surface configuration. The respective upper and lower surfacesdefining the gap may also possess alternative geometries such asarcuate, semi-circular, etc, which provide generally non-parallelsurfaces that change the angle of heat radiation incidence and improvethe reflective loss as compared with parallelly disposed facingsurfaces. To provide enhanced thermal isolation of the upper end of thevaporizing device 100 from the vaporizer core 130, the illustratedembodiment is provided with a selectively removable passive thermalinsulator 106. As illustrated, the passive thermal insulator 106 isbifurcated and retained in the gap by insulator retainer 105, such as aresilient o-ring. Alternatively, the thermal insulator 106 may bepermanently situated in the gap 108 by molding or casting.

The non-parallel contouring or tapering of the thermal isolation gap 108provides one or more of the following advantages including: 1)increasing the structural integrity and strength of the vaporizer body,particularly with respect to resisting increased pressures generated byliquid sample vaporization within the vaporizer core 130; 2) maximizingcontact area between the surfaces of the thermal insulator 106 and theconfronting surfaces of the tapering isolation gap 108 and minimizingpotential separation by the applied compressive radial hoop force fromthe insulator retainer 105; 3) reducing the risk of condensationformation between the thermal insulator 106 and the body 102 at theirinterface in the isolation gap 108; 4) allowing the material forming thethermal insulator 106 to avoid tensile failure; and 5) improving radiantheat rejection through reflection by providing a larger aperture surfacearea. As described below with respect to FIG. 2, the thermal insulator106 may optionally incorporate features to provide active coolingelements such as a subsystem based on a looped unheated liquid by-pass.

Moving to the physical characteristics of the passive thermal insulator106, it is preferably composed from a dimensionally stable, relativelyrigid, very low thermally conductive material such as foamed alumina orcalcium silicate glass/fibers, foamed ceramic, etc. The material isformed/molded into a trapezoidal, toroidal configuration dimensionallycorresponding to the conformation of the gap 108. The insulator 106 canbe cut into two confrontable mating pieces each featuring a centralcutout/kerf dimensionally corresponding to the axial segment throughwhich the channel 120 passes in the body 102. Consequently, the thermalinsulator 106 establishes thermal isolation between the upper and lowerportions of the body 102 by way of the tapered thermal isolation gap 108and minimizes the risk of undesirable liquid sample pre-vaporizationbefore it reaches the vaporizer core 130. By minimizing and/oreliminating heat migration from the vaporizer core 130 to the upperportion of the body 102, pre-vaporization above the vaporizer core isreduced which leads to enhanced sample uniformity and increased accuracyof sample analysis. Furthermore, the issue of ice formation on theexterior of the body 102 proximate to the ports 104 attributable to suchpre-vaporization is reduced.

Turning now to the vaporization elements associated with the vaporizercore 130 when the vaporizer device 100 is fully assembled, and referringparticularly to FIG. 1F, the vaporizer core 130 encloses a heatingassembly that can include an insertion cartridge heater or heatingelement 131, an optional metal sheath 132 made of brass, copper oranother material for conducting heat and an overlying heater housing 133made of stainless-steel or other metal. The insertion cartridge heater131 is powered by electrical feed lines 112 and controlled via athermocouple 110 both projecting from the base of the body 102.Alternatively, or in addition to, the body 102 may feature a bore and/orprotrusion near the outlet port 118 to accommodate a thermowell havingan additional thermocouple that detects the temperature of the vaporizedsample leaving the vaporizer as described further with respect to FIGS.4 and 5.

The thermocouple 110 is connected to a proportional-integral-derivative(PID) controller and/or Programmable Logic Controller (PLC) (not shown),such as an Allen Bradley 850 series PLC or equivalent controller, toprovide signal feedback and control of the vaporizer device 100. Themetal sheath 132 engirds the cartridge heater 131 to promote uniformdistribution of heat from the heater 131 to the overlyingstainless-steel heater housing 133. The sheathed cartridge 131 is seatedsnuggly, preferably by compression and, in turn, the stainless-steelhousing 133 dimensionally conforms to the inner surfaces of the steppedbore 135 for insertion therein. The upper end of the stainless-steelheater housing 133 has a diameter less than that the vaporizer core 130and projects to an axial position leaving a gap 128 to permit liquidsample flow from the channel 120 to an area between an outer surface ofthe heater housing 133 and an inner surface of the bore 135. Thediameter of the non-reactive housing 133 is stepped diametrically fromthe upper end to the lower end in a fashion to accommodate a foraminousnon-reactive, stainless steel wire mesh 129, a stepped ring to establishthe vapor annulus 137 between the body 102 and the stainless steelhousing 133, and a mounting fixture 136 for secure, sealing attachmentto the body 102.

The foraminous non-reactive, stainless steel wire mesh 129 is disposedabout the upper step portion of the heater housing 133 and dimensionedto fill the area between the step of the housing 133 and the interiorsurface of the bore 135. Flash vaporization is achieved upon liquidsample contact with the wire mesh by efficient transfer of heat energyfrom the electrical cartridge heater 131 via the heat distributionsheath 132 to and uniformly through the non-reactive housing 133. Thewire mesh 129 provides a variety of advantages. First, utilization ofthe wire mesh 129 tends to maximize and otherwise provide a very largeheat transfer surface area for transferring heat outwardly from thehousing 133 to obtain uniform liquid flow and vaporization, and anessentially homogeneous vapor that is representative of the liquidsample composition.

More specifically, the mesh 129 acts as a diffuser which aids in theformation of uniform flow passing through the housing 102 and at theoutlet 118. This uniform flow enhances the heating and ultimatevaporization of liquids while also reducing hot spots and the formationsof deposits within the vaporizer core 130. Further, the mesh 129 acts asa thermal transfer path thereby allowing heat to be carried away fromthe heater housing 133 and into the fluid flow path between the housing133 and the inner surface of the bore 135. The mesh 129 also encouragesmixing which promotes thermal transfer to fluid passing through andaround the mesh 129. Accordingly, the use of the mesh 129 havingaugmented heat characteristics from the housing 133 effectivelyincreases the surface area of heated liquid in the cavity between thehousing 133 and the inner surface of the bore 135. Further, the transferof fluid through and around the mesh 129 impedes the egress of liquidfrom the vaporizer core 130 thereby ensuring adequate heating of thetraveling liquid. These advantageous features provide for enhancedvaporization of liquids passing through the vaporizer core 130 therebyreducing or eliminating the output of unvaporized liquid which coulddamage a downstream analyzer.

Use of the mesh 129 or highly porous material maximizes the surface areafor heat transfer to the cascading input liquid sample, which in thecase of LNG results in a 600-fold volumetric expansion, and alsoestablishes a vapor transit passage to exit though the vapor annulus 137into the vapor outlet passage 140 and to the vapor sample discharge port118. Where pre-formed as a tubular element, the mesh 129 should bedimensioned to possess thickness sufficient to fill all space between anouter surface of the upper end of the housing 133 and the inner surfaceof the bore 135 below the gap 128 such that the mesh 129 maintainscontact with both the housing 133 and the interior surface of the bore135. In one embodiment, the mesh 129 may be crimped and spirally wrappedabout the housing 133 to permit some radial compression upon insertioninto the stepped bore 135. Once inserted into the stepped bore 135, themesh 129 can be allowed to unwrap thereby filling the area between theouter surface of the housing 133 and the interior surface of the bore135.

In one embodiment, the mesh 129 can be uniformly bent as illustrated inFIG. 1G. In this example, the mesh 129 is provided with a series ofalternating bends 134 formed so that when the mesh is coiled around thehousing 133, the bends 134 do not nest within each other on subsequentwraps. Nesting of the bends 134 is undesirable as it both prevents themesh 129 from expanding and also reduces the ease of installation andadjustment of the mesh 129. By providing a non-parallel linear bend toeither edge of the mesh 129 (when uncoiled), and repeating the bend inan alternating direction across the mesh length, the mesh 129concomitantly avoids nesting and expands substantially uniformly to fillthe area between the outer surface of the housing 133 and the innersurface of the bore 135.

The housing 102 also includes a first axially disposed o-ring seal 138located proximate to and between the collecting annulus 137 and interiorthreading 141 formed at the base of the stepped bore 135 for threadedlyco-acting with mating threading on the exterior surface of thestainless-steel housing 133 to seal the vaporizer core 130 within thebody 102. To further ensure a complete seal to prevent any leakage ofvaporized gas, the annular face of the body 102 may include an o-ring139 for compression against confronting mating face of thestainless-steel heater body of the mounting fixture 136. In theillustrated single path version of the vaporizer device 100, the liquidsample is introduced to the vaporizer device 100 via a port 104 (aportion of which enters the channel 120 at a rate dictated by themetering valve stem 107), passes through the thermal separation zonedefined by the gap 108, to the vaporizer core 130 to flash vaporize andpass, under the pressure of vaporization, into the collecting annulus137 to exit the vaporizer through port 118.

Accordingly, pre-vaporization of a liquid sample introduced at the upperportion of the vaporizer device is avoided by thermally isolating theupper portion from the flash vaporization core 130 of the vaporizerdevice 100.

The vaporizer housing 102 can be crafted from a single unit of acorrosion-resistant super alloy such as stainless-steel or aluminum. Thevaporizer core 130 can be step-bored from a bottom portion of thehousing 102 using a boring bar on a lathe to radially provide spacewithin the housing 102 for the annulus 137 and wire mesh 129. The axiallength of the vaporizer core 130 is bored to a length which is slightlymore than the axial length of the housing 133 such that when the housing133 is fitted within the vaporizer core 130, a gap 128 is formed betweenthe top of the housing 133 and the output of the channel 120. Thechannel 120 can be bored using a drill bit passing through thealready-bored vaporizer core 130 and extends to the axial port 104Awhich is axially bored from the top of the housing 102. Radial ports104R can be radially bored from the side of the housing 102 andpassageways 113 can be bored with smaller bits using the already boredradial ports 104R to connect the radial ports 104R to the axial port104A and the channel 120. Another bore is formed between the ports 104and the isolation gap 108 along the axial length of the housing 102 inorder to provide for the adjustable valve 107. This bore can then beused to machine a stepped bore orthogonally formed across across-section of the channel 120 thereby providing a seat for the valve107 to control flow within the channel 120.

In FIGS. 2A/2B and FIGS. 3A/3B, active cooling embodiments of vaporizerdevices 200 and 300 are respectively illustrated. The embodimentsillustrated in FIGS. 2A/2B and 3A/3B are similar to the embodimentillustrated in FIG. 1 but further feature an active cooling adjunct toinsure against heat transfer to the upper portion of the vaporizer andpre-vaporization of the liquid sample. FIGS. 2A and 2B illustrate anintegrated flow channel take-off 202 from channel 120 located above theisolation gap 108 to provide for liquid flow to a loop 204 formed inthermal insulator 106. Accordingly, in this embodiment, a portion of theliquid introduced into channel 120 flows through the channel 202 to theloop 204 to provide an active cooling component to the insulator 106. Anoutlet (not illustrated) for the liquid passing through loop 204 may beconnected to a liquid discharge port 104 or recirculated into the liquidfeed stream at an input port 104R or passageway 113.

In FIGS. 3A and 3B, an active cooling loop take-off 302 (represented bydotted lines) is connected at an input port 104R to provide liquidsample to a tube 304 embedded in and encircling the insulator 106. Theoutlet of the tube 304 (not illustrated) can be connected to anotherliquid discharge port 104R from the vaporizer device 300 to provide acontinuous flow of cooling liquid therethrough. In this case, thetakeoff is provided by a flow channel takeoff proximate to the inputport 104R wrapping around and embedded in an annulus formed in theinsulator 108. Unheated liquid is taken off at the input at the inletport 104R passed through the active cooling circuit, illustrated as atubular loop with a liquid fluid tube, to a drain/outlet (notillustrated) connected to a discharge speed loop or the like. In thismanner a fresh supply of cooling liquid can be utilized to augmentcooling to prevent the upper portion of the body 102 from heating. Thus,the risk of pre-vaporization before entry of the liquid sample to thevaporizer core 130 is minimized.

FIG. 4A is a perspective cut-away view of a vaporizer device 400 havingan alternative tapered metering valve stem 402 in accordance with anembodiment of the invention. The tapered metering valve stem 402 isprovided within a cavity 403 radially bored into the body 102 axiallybetween the passageway 113 and the thermal isolation gap 108. Thetapered metering valve stem 402 can include thereon a plurality ofo-rings 404, 408, or the like, that seal and provide pressure controlwithin the cavity 403. The cavity 403 can include a threaded portion 407allowing for the tapered metering valve 402 to rotate and radiallytraverse a predetermined distance within the cavity 403. The taperedmetering valve stem 402 further includes a substantially central groove406 which is circumferentially tapered to a reduced diameter withrespect to surrounding portions of the tapered metering valve 402 stemthereby allowing liquid to flow around the metering valve stem 402 andthrough throat or channel 120. The degree of blockage by the taperedmetering valve stem 402 of the channel 120 flow path is adjustable viaan adjustor element 401. The adjuster element 401 which may take theform of a slotted screw head, rotates relative to the threading 407 totranslate the groove 406 of the metering valve stem 402 radiallyrelative to the channel 120. Thus, the amount at which liquid flow iscontrolled is dictated by a location of the tapered groove 406 withrespect to the channel 120. An automated alternative to the manualadjustor element 401 would involve the metering valve stem 402 beingassociated with an actuatable motor (not illustrated) to controladjustment of the position of the valve stem 402. A cap or plug 410 isprovided at an end of the metering valve 402 opposite the adjustableelement 401 to enclose the cavity 403, prevent pressure-inducedexpulsion of the metering valve stem 402 and limit the travel of themetering valve 402 within the cavity 403. The cap or plug 410 can beexternal to the vaporizer device or included within the cavity 403 suchthat it is flush with the body 102.

FIG. 4B is a perspective cut-away view of the vaporizer device 400having the tapered metering valve 402 in accordance with an embodimentof the invention. Here, the tapered metering valve 402 is the same asthat described with respect to FIG. 4A and therefore like designationsare repeated. However, it should be noted that the implementation of theadjustable metering valve 107 of the vaporizer device 100 illustrated inFIGS. 1D-1F could be incorporated into the vaporizer device 400 insteadof the tapered metering valve 402 structure.

Also illustrated in FIG. 4B is the inclusion of an additionalthermocouple 416 proximate the outlet port 118 and provided within athermowell 417 formed within a protrusion, such as a machined boss 412,protruding from the heater housing 133 as illustrated in FIG. 4A. Thethermowell 417 is angled such that an upper portion of the thermowell417, and thermocouple 416 therein, are positioned proximate the outletport 118 at a high velocity flow region to provide enhanced sensitivityand more accurate readings as to the temperature of gas samples exitingthe vaporizer device 400. The presence of the machined boss 412increases the temperature sensitivity without restricting the flow ratein any substantial manner.

As with the thermocouple 110, the thermocouple 416 can be connected vialead 414 to a proportional-integral-derivative (PID) controller and/orProgrammable Logic Controller (PLC) (not shown), such as an AllenBradley 850 series PLC or equivalent controller, to provide signalfeedback and control of the vaporizer device 400. This allows for thecreation of a control loop for continuously monitoring and controllingthe temperature of gas samples exiting the vaporizer device 400.Accordingly, based on the equipment that is connected to the vaporizerdevice 400, the temperature can be controlled to ensure that gas exitingthe vaporizer device 400 will not damage the downstream equipment. Theinclusion of the thermocouple 416 proximate the outlet port 118 alsoprovides the advantage of being able to monitor undesirably hightemperatures that could be the result of a no flow condition in which noliquid is flowing through the vaporizer device 400. Thus, the interiorlypositioned thermocouple 416 improves upon remote sensing of the outletgas temperature with a sensing device attached to the outlet as such aremote device would not be able to detect high heater temperaturesresulting from a no flow condition thereby risking a burnout that coulddestroy the heating element and render the vaporizer device 400inoperative. The installation of the thermocouple 416 within the housingalso provides for less failure modes during assembly of the vaporizerdevice 400 while also providing for simpler wiring to the control systemwhich often times requires meeting explosion proof design code.

FIGS. 5A and 5B are perspective cut-away views of a vaporizer device 500having the metering valve 402 in accordance with an embodiment of theinvention. Here, the tapered metering valve 402 is the same as thatdescribed with respect to FIG. 4A and therefore like designations arerepeated. However, it should be noted that the adjustable metering valve107 of the vaporizer device 100 illustrated in FIGS. 1D-1F could beincorporated into the vaporizer device 500 instead of the taperedmetering valve 402 structure.

Also illustrated in FIGS. 5A and 5B is the inclusion of an additionalthermocouple 516 proximate the outlet port 118 and provided within astraight thermowell 517 formed within the heater housing 133. Thethermowell 517 is axially bored so as to run parallel with the housing133 and proximate the outlet port 118. A thermocouple 516 providedwithin the thermowell 517 is positioned proximate the outlet port 418 ata high velocity flow region to provide enhanced sensitivity and readingsas to the temperature of gas samples exiting the vaporizer device 500.

As with the thermocouple 110, the thermocouple 516 can be connected vialead 514 to a proportional-integral-derivative (PID) controller and/orProgrammable Logic Controller (PLC) (not shown), such as an AllenBradley 850 series PLC or equivalent controller, to provide signalfeedback and control of the vaporizer device 500. This allows for thecreation of a control loop for continuously monitoring and controllingthe temperature of gas samples exiting the vaporizer device 500.Accordingly, based on the equipment that is connected to the vaporizerdevice 500, the temperature can be controlled to ensure that gas exitingthe vaporizer device 500 will not damage the downstream equipment. Theinclusion of the thermocouple 516 proximate the outlet port 118 alsoprovides the advantage of being able to monitor undesirably hightemperatures that could be the result of a no flow condition in which noliquid is flowing through the vaporizer device 500. Thus, the interiorlypositioned thermocouple 516 improves upon remote sensing of the outletgas temperature with a sensing device attached to the outlet as such aremote device would not be able to detect high heater temperaturesresulting from a no flow condition thereby risking a burnout that coulddestroy the heating element and render the vaporizer device 500inoperative. The installation of the thermocouple 516 within the housingalso provides for less failure modes during assembly of the vaporizerdevice 500 while also providing for simpler wiring to the control systemwhich often times requires meeting explosion proof design code.

It should be appreciated that other well-known cooling adjuncts may beutilized in lieu of the above-described active cooling subsystem. Theperceived advantage of the above-described systems is that they rely onthe simple expedient of diverting a small amount of the liquid takeoffsample for cooling and either reinjecting that diverted amount back intothe pipeline or passing it though any one of well-knowncollection/recirculation systems.

It should be understood for a person having ordinary skill in the artthat a device or method incorporating any of the additional oralternative details mentioned above would fall within the scope of thepresent invention as determined based upon the claims below and anyequivalents thereof. Other aspects, objects and advantages of thepresent invention should be apparent to a person having ordinary skillin the art given the drawings and the disclosure.

1. A vaporizer for vaporizing a multi component hydrocarbon containingliquid mixture, comprising: a generally elongated tubular body having afirst segment defining a first end and a second segment defining asecond end; a liquid sample port connected to a liquid passage formedintegrally in the first segment, where said liquid sample port providesfor liquid input; a liquid channel disposed generally longitudinallyalong a central axis of the vaporizer and extending substantially in thedirection of elongation of said tubular body, said liquid channel havinga first end and a second end, said first end of said liquid channelintersecting with said liquid passage to provide a flow path for liquidfrom said liquid sample port therethrough along its length; a liquidflow control element disposed within said first segment of said tubularbody and configured to intersect the liquid channel; a gap formed in andextending from an exterior surface of the tubular body, the gap defininga generally non-parallel surface directed inwardly toward the liquidchannel and disposed along the length of the liquid channel; a vaporizercore internal to and extending from said second end of said tubular bodyto said second end of said liquid channel; a heating assemblydimensioned for insertion into the vaporizer core and sealinglysecurable to said tubular body, said heating assembly having a flashvaporizing heating element that vaporizes liquid introduced from saidliquid channel; and a vapor discharge outlet port formed in said tubularbody in said second segment spaced from said second end of the tubularbody and intersecting with said vaporizer core.
 2. The vaporizer ofclaim 1 wherein the body is cylindrical and the first segment is anupper segment disposed above the second segment, the cylindrical bodyfurther comprising: a second liquid sample port connected to said liquidpassage formed integrally in the first segment, where said second liquidsample port provides for liquid discharge; and a thermal insulatordisposed within the gap.
 3. The vaporizer of claim 2, wherein thegenerally non-parallel surface of the gap is tapered flat and planar,and the liquid sample port and the second liquid sample port areorthogonally disposed relative to the other.
 4. The vaporizer of claim3, wherein the liquid sample port is disposed along an axis of thecylindrical body.
 5. The vaporizer of claim 4 further includingcomprising: an active cooling circuit established by a liquid takeoffproximate a liquid fluid tube within said thermal insulator to minimizeheat transfer from said second segment to said first segment.
 6. Avaporizer device for vaporizing a multi component hydrocarbon containingliquid mixture, comprising: a body; one or more ports configured toreceive a liquid sample through the body; a channel configured toreceive the liquid sample from the one or more ports; a recessed taperedthermal isolation gap formed on an exterior of the body and radiallysurrounding the channel, the recessed tapered thermal isolation gapbeing configured to receive and retain a thermal insulator; a heatingassembly configured to vaporize the liquid sample exiting the channel,the heating assembly being affixed within the body; and an outletconfigured to output a vaporized liquid sample.
 7. The device as claimedin claim 6, wherein the heating assembly includes a heating element anda metal housing enclosing the heating element.
 8. The device as claimedin claim 7, wherein the heating element is enclosed within a metalsheath.
 9. The device as claimed in claim 8, wherein the metal housingis at least partially enclosed by a metal mesh.
 10. The device asclaimed in claim 6, wherein the recessed tapered thermal isolation gapis filled with an insulative material.
 11. The device as claimed inclaim 10, wherein the insulative material is selected from the groupconsisting of alumina silicate, calcium silicate, and foamed ceramics.12. The device as claimed in claim 6, wherein the recessed taperedthermal isolation gap tapers inwardly toward the channel.
 13. The deviceas claimed in claim 6, further comprising: a liquid flow control elementconfigured to intersect the channel to control a flow of the liquidsample entering the channel.
 14. The device as claimed in claim 6,wherein the heating assembly is affixed within a vaporizer core, thevaporizer core being an opening formed within the body and having aradial and axial length larger than the heating assembly therebycreating a liquid flow path from the channel to the area between theouter surface of the heating assembly and the inner surface of the bodyand to the outlet.
 15. The device as claimed in claim 6, wherein therecessed tapered thermal isolation gap includes a cooling circuit cooledby liquid takeoff from a port.
 16. The device as claimed in claim 6,wherein the heating assembly includes a temperature sensor thereinconfigured to align with the outlet port of the vaporizer device, thetemperature sensor providing a temperature of the vaporized sample atthe outlet port.
 17. The device as claimed in claim 16, wherein thetemperature sensor is affixed within a thermowell interior and parallelto an axial length of the heater assembly.
 18. The device as claimed inclaim 16, wherein the temperature sensor is affixed within a thermowellformed at an angle within a protrusion from the heater assembly. 19-20.(canceled)